Biological Research

Question 1

Methodology

Answer 1

IV= NGRI murderers
DV= Brain differences

Quasi, Matched Pairs

Experimental: 41 murderers, 6 schizophrenia, 2 epilepsy

39 men 2 women

Control: Matched on age, sex, IQ

Question 2

Procedures

Answer 2

Opportunity sampling

FDG tracer used by active brain areas

1. Injected with tracer then P’s practiced CPT
2. 30s before PET they started the CPT so no novelty
3. 32min after injection, PET scan, 10 horizontal brain slices (analysed 6 cortical, 8 subcortical)
4. Compared NGRI results to control

Precise details given of scanning techniques so can replicate

Question 3

Findings

Answer 3

Reduced activity in areas linked to violence:
•Frontal lobe
•Left Amygdala

Increased activity:
•Cerebellum
•Right amygdala

Normal:
•Midbrain

They had abnormal asymmetries

Question 4

Conclusions

Answer 4

Murderers pleading NGRI have different brain functioning

However, biological processes that cause violence are complex and can’t be reduced to single brain function

Violence likely caused by disruption in a network of brain functions

IQ and head injuries may have confounded study

Warnings: Violent behaviour not just bio, NGRI murderers still responsible, doesn’t prove brain dysfunction cause violence (could be other way arounnd), violent isn’t fully explained by the PET scans

Question 5

Methodology/ Procedures evaluation

Answer 5

PET scans = Objective, scientific, high validity. Can apply findings

Questionable whether in right mind to understand right to withdraw/ give informed consent, were they vulnerable?

Psychological harm if didn’t understand what’s involved in PET scan